Brown tetrazo dye.



vtor of philosophy, chemist, citizen of the STATESEEENT OFFICE."

osc'anoimrntnn F ELBERF LD GERMANY, ASSIG-NOR TO FARZBENFABRIKEN voEM. FBIEDR. BAYER & 00., 0F En-BEREELD, GERMANY, A COBPORATION'OF GERMANY.

BROWN TEE DRAZO DYE.

Specification of Letters Patent. Patented Mar. 5, 1912.

toraear. I

Application filed July 13, 1911. Serial No. 638,309.

No Drawing.

pound of para-para'-diaminodiphenylurea- To all whom it may concern:

meta -meta-d1sulfon1c acid.

Be it known that I, OSCAR GiiNTHER, doc- German Empire, residing at Elberfeld, Germany, have invented new and useful Improvements in Brown Tetrazo Dye, of which the following is a specification. mm 3 My invention relates to the manufacture and production of a new disazo dye which is h new d having most probably the obtained by combining the tetrazo comformula: v 4

a reddish-violet coloration; yielding upon The following'example is given the parts being by weightz-402 parts of the tetrazo i NHr- -N=-N -NH.OO.NH 16! I 803R is after being dried and pulverized in the shape of its sodium salt a dark powder which is soluble'in concentrated sulfuric acid with nodiphenylurea-meta-meta'-disulfonic acid by tetrazotizing this compound with sodium nitrite and 01H (see United States Letters Patent No. 687171 of Nov. 19, 1901) ailowed to run into a Weak alkaline solution of 215 parts of metaphenylenediamin. The dye is salted out with common salt filtered oil and dried; I claim 4 The herein described new tetrazo dyestufl' having most'probably the formula:

reduction With'stannous chlorid and hydrochloric acid 1.2.4-triaminobenz'ene and 4.4 diaminodiphenylurea 3.3 disulfonic acid which is split up into CO and parapheny len'ediamin sulfonic acid. The new coloring matter dyes cotton directly a yellow brown, which when developed with diazotized para nitranilin changes into a full reddish-brown which can be discharged to a pure white and is of excellent fastness to washing andt-o light.

which is after being dried and pulverized reddish-brown which can be discharged to in the shape of its sodium salt a dark powa pure white and is of excellent :t'astness-to der soluble inconcentrated sulfuric acid washing and to light, substantially as dowith a reddish-violet coloration; yielding scribed.

upon reduction with stannous chlorid and In testimony whereof I have hereunto sethydrochloric acid 1.2.4-triaminobenzene and my hand in the presence of two subscribing 4A diaminodiphenylurea 3.37 disulfonic witnesses.

acid which latter compound is further split up into CO and para-phenylenediamin sulfonic acid; dyeing cotton directly a yellow brown, which when developed with diazotized para-nitranilin changes into a full OSCAR GUNTHEE. [11.5.]

Witnesses:

ALBERT F. NUPER, ALFRED HENKEL.

compound obtained from para-paraJ-diamiwith two molecules of meta-pheriylenedia- 

